Unexpected Data Loss in TCP Socket with Python 3.11 and Custom Buffer Management
I've tried everything I can think of but I've been banging my head against this for hours..... I'm experiencing a frustrating scenario with my TCP socket implementation in Python 3.11. The application is designed to send and receive data to a remote server, but I've noticed that sometimes data gets lost during transmission without any errors being thrown. I'm using a custom buffer management strategy to handle incoming data, which seems to be part of the question. Here's a simplified version of my code: ```python import socket import threading BUFFER_SIZE = 1024 class SocketClient: def __init__(self, host, port): self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) self.sock.connect((host, port)) self.buffer = b'' def send_data(self, data): self.sock.sendall(data) def receive_data(self): while True: part = self.sock.recv(BUFFER_SIZE) if part: self.buffer += part if b'END' in self.buffer: self.process_buffer() else: break def process_buffer(self): # Process the full message in self.buffer complete_data = self.buffer.decode('utf-8') print('Received:', complete_data) self.buffer = b'' client = SocketClient('remote.server.com', 12345) threading.Thread(target=client.receive_data).start() while True: client.send_data(b'Test message') ``` I've ensured that the server is capable of handling the incoming data correctly, and I'm using `sendall` to make sure all data is sent. However, occasionally the `process_buffer` method processes incomplete data, leading to missing pieces of information. I've attempted adjusting the `BUFFER_SIZE`, but that hasn't resolved the scenario. I also checked the server logs and didn't see any indications of dropped or corrupted packets. I'm wondering if there might be an scenario with how I'm concatenating the received data or if I need to implement a more robust method for message boundaries, especially since I'm using a custom marker (`END`). Any suggestions on how to improve this implementation or any common pitfalls I might be overlooking? For context: I'm using Python on Ubuntu. Any help would be greatly appreciated!